<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>固态定位</title>
    <style>
        .w {
            width: 1200px;
            height: 3000px;
            margin: 0px auto;
            background-color: orange;
        }
        .ffix {
            position: fixed;
            left: 50%;
            top: 200px;
            margin-left: 605px;
            width: 100px;
            height: 200px;
            background-color: skyblue;
        }
    </style>
</head>
<body>
    <p>相对版心右侧指定距离</p>
    <div class="ffix"></div>
    <div class="w"></div>
</body>
</html>